
The picture's not very clear, so in case it helps, this is a drawing I made years ago of part of the scene, copied from another photograph:

A very small colour version of the painting is online at http://www.gsei.com.cn/lvyou/jindian/jiayuguan/default.htm
Now, most of the cavalry clearly wear splint helmets and scale body-armour, and many of you will recognise this painting as one of the sources for the Three Kingdoms cavalry in Chris Peers' Osprey Imperial Chinese Armies (1), plate E1, and also in Liu Yonghua's Ancient Chinese Armour (page 49). At the very head of the procession is an unarmoured figure, perhaps an official, followed by three more such unarmoured figures.
But the figures I am interested in are these two:

What are they wearing? Both have short, roughly hip-length, red garments with elbow-length sleeves - the forearms are white, presumably representing a garment worn under the red one - and possibly high collars. This is about the same "cut" as Han iron lamellar armour. Could these garments be red leather lamellar armours? Or some sort of cloth-covered armour? At the hem of one rider's garment I can see - in some photos, at least! - some short vertical lines that might mark armour lamellae (though if so, why are they on the edge only?) or a decorative border.
Any ideas? Any parallels to this garment from around the same period?
cheers,
Duncan